libertas: fix return value when processing invalid packet

Nothing actually uses the return value yet, but we might as well
make it correct, like process_rxed_802_11_packet() does for the
same case. Also ensure that if monitor mode is enabled (and
thus process_rxed_802_11_packet() is called) that the debugging
enter/leave functions are balanced.

Signed-off-by: Dan Williams <[e-mail]>
Signed-off-by: John W. Linville <[e-mail]>

drivers/net/wireless/libertas/rx.c

···
 
 	skb->ip_summed = CHECKSUM_NONE;
 
-	if (priv->wdev->iftype == NL80211_IFTYPE_MONITOR)
-		return process_rxed_802_11_packet(priv, skb);
+	if (priv->wdev->iftype == NL80211_IFTYPE_MONITOR) {
+		ret = process_rxed_802_11_packet(priv, skb);
+		goto done;
+	}
 
 	p_rx_pd = (struct rxpd *) skb->data;
 	p_rx_pkt = (struct rxpackethdr *) ((u8 *)p_rx_pd +
···
 	if (skb->len < (ETH_HLEN + 8 + sizeof(struct rxpd))) {
 		lbs_deb_rx("rx err: frame received with bad length\n");
 		dev->stats.rx_length_errors++;
-		ret = 0;
+		ret = -EINVAL;
 		dev_kfree_skb(skb);
 		goto done;
 	}